Shandong Gettop Acoustic Co., Ltd.

Silicon Matrix Pte Ltd.

Wang Zhe

Miao Yubo

Chong Ser Choong

Xin Ping Cao

Various embodiments of a silicon microphone sensing element without dedicated backplate are disclosed. The microphone sensing element has a circular or polygonal diaphragm with a plurality of perforated springs suspended above the front side of a conductive substrate. The diaphragm is aligned above one or more back holes in the substrate having a front opening smaller than the diaphragm. In one embodiment, a continuous perforated spring surrounds the diaphragm and has a shape that conforms to the diaphragm. A plurality of perforated beams connects the spring to rigid pads that anchor the movable diaphragm and spring. In another embodiment, there is a plurality of perforated springs having double or triple folding configurations and a plurality of perforated beams connecting the diaphragm to rigid pads. Also disclosed is a scheme to integrate the silicon microphone sensing element with CMOS devices on a single chip.

Silicon microphone without dedicated backplate

The MEMS package has a mounting substrate on which one or more transducer chips are mounted wherein the mounting substrate has an opening. A top cover is attached to and separated from the mounting substrate by a spacer forming a housing enclosed by the top cover, the spacer, and the mounting substrate and accessed by the opening. Electrical connections are made between the one or more transducer chips and the mounting substrate and/or between the one or more transducer chips and the top cover. A bottom cover can be mounted on a bottom surface of the mounting substrate wherein a hollow chamber is formed between the mounting substrate and the bottom cover, wherein a second opening in the bottom cover is not aligned with the first opening. Pads on outside surfaces of the top and bottom covers can be used for further attachment to printed circuit boards. The top and bottom covers can be a flexible printed circuit board folded under the mounting substrate.

Double-side mountable MEMS package

A silicon based microphone sensing element and a method for making the same are disclosed. The microphone sensing element has a diaphragm with adjoining perforated plates on the front side of a conductive substrate. The diaphragm is aligned above a back hole in the substrate wherein the front opening of the back hole is smaller than the diaphragm. The diaphragm is supported by mechanical springs each having one end attached to the diaphragm and another end connected to a rigid pad anchored on a dielectric spacer. The diaphragm, perforated plates, and mechanical springs are preferably made of the same film and are suspended above an air gap that overlies the substrate. A first electrode is formed on one or more rigid pads and a second electrode is formed at one or more locations on the substrate to establish a variable capacitor circuit. Different embodiments are shown that reduce parasitic capacitance.

Backplateless silicon microphone

A backplateless silicon microphone and a wire protection method for improved impact resistance are disclosed. A circular diaphragm is surrounded by a circular spring having a plurality of slots and perforations to facilitate air damping reduction, release of in-plane stress, and improve out-plane flexibility. Anchored at a substrate, the circular spring holds the silicon microphone suspended over a backside hole in the substrate but allows the diaphragm to vibrate perpendicular to the substrate. A microphone variable capacitor is formed between the perforated spring and substrate. Slot size is minimized to prevent particles from entering an underlying air gap. A plurality of 'n' bonding pads near the outer edge of the circular spring are connected by 'n/2' bonding wires that serve as a stopper to restrict an upward motion of the diaphragm. The bonding wires may cross each other to enable lower loop height for more effective resistance to impact.

Silicon microphone with enhanced impact proof structure using bonding wires

The MEMS package comprises a first and a second pre-molded lead-frame substrate, at least one of them having a cavity formed by plastic sidewalls along its periphery. The first and second pre-molded lead-frame substrates are interconnected with metal leads. At least one MEMS device is attached to one of the substrates. The first pre-molded lead-frame substrate is folded over and joined to the second pre-molded lead-frame substrate to house the at least one MEMS device. In one embodiment, the first pre-molded lead-frame substrate has metal leads extending outside of sidewalls of the cavities. The extended metal leads are folded over the top of the second pre-molded lead-frame substrate to form surface mounting pads. In some embodiments, extended metal leads are folded along the sidewalls and connected to ground for electromagnetic interference (EMI) shielding.

Folded lead-frame packages for MEMS devices

A Micro Electro Mechanical Systems (MEMS) G-switch includes one or more actuators formed between fixed driving stages and moveable driving stages. A proof mass is attached to the moveable driving stages and flexibly attached to a substrate through one or more spring members. A voltage control circuit applies working voltages to the driving stages. With a first working voltage applied between the moveable and the fixed driving stages, moving of the driving stages' sensing direction towards gravity at a first critical angle will cause moveable driving stages to collapse and touch the fixed driving stage on the substrate and thus turn on the MEMS G-switch. After turning on the G-switch, a second working voltage is applied and moving of the driving stages' sensing direction away from gravity at a second critical angle will cause moveable electrodes to deviate from the fixed electrodes and thus turn off the MEMS G-switch.

MEMS G-switch device

A MEMS package and methods for its embodiment are described. The MEMS package has at least one MEMS device mounted on a flexible and foldable substrate. A metal cap structure surrounds the at least one MEMS device wherein an edge surface of the metal cap structure is attached to the flexible substrate and wherein a portion of the flexible substrate is folded under itself thereby forming the MEMS package. A meshed metal environmental hole underlying the at least one MEMS device provides enhanced EMI immunity.

MEMS packaging method for enhanced EMI immunity using flexible substrates

A MEMS microphone with a stacked PCB package is described. The MEMS package has at least one MEMS acoustic sensor device located on a PCB stack. A metal cap structure surrounds the at least one MEMS acoustic sensor device wherein an edge surface of the metal cap structure is attached and electrically connected to the PCB stack. In a first embodiment, a back chamber is formed underlying the at least one MEMS acoustic sensor device and within the PCB stack wherein an opening underlying the at least one MEMS acoustic sensor device accesses the back chamber. An opening in the metal cap structure not aligned with the at least one MEMS acoustic sensor device allows external fluid, acoustic energy or pressure to enter the at least one MEMS acoustic sensor device. In a second embodiment, a back chamber is formed in the space under the metal cap and over the first PCB. A hollow chamber is formed between the first PCB and the second PCB wherein an opening under the at least one MEMS acoustic sensor device accesses the hollow chamber. An opening in a bottom surface of the PCB stack not aligned with the at least one MEMS acoustic sensor device also accesses the hollow chamber and allows external fluid, acoustic energy or pressure to enter the at least one MEMS acoustic sensor device.

MEMS microphone with a stacked PCB package and method of producing the same

A silicon based microphone sensing element and a method for making the same are disclosed. The microphone sensing element has a diaphragm with a perforated plate adjoining each side or corner. The diaphragm is aligned above one or more back holes created in a conductive substrate wherein the back hole has a width less than that of the diaphragm. Perforated plates are suspended above an air gap that overlies the substrate. The diaphragm is supported by mechanical springs with two ends that are attached to the diaphragm at a corner, side, or center and terminate in a rigid pad anchored on a dielectric spacer layer. A first electrode is formed on one or more rigid pads and a second electrode is formed at one or more locations on the substrate to establish a variable capacitor circuit. The microphone sensing element can be embodied in different approaches to reduce parasitic capacitance.

A microphone sensing element and a method for making the same are disclosed. The sensing element has a diaphragm and an attached electrical lead-out arm preferably made of polysilicon that are separated by an air gap from an underlying backplate region created on a conductive silicon substrate. The backplate region has acoustic holes created by removing an oxide filling in a continuous trench that surrounds hole edges and by removing oxide to form the air gap. The diaphragm is softly constrained along its edge by an elastic element that connects to a surrounding rigid polysilicon layer. The elastic element is typically a polymer such as parylene having a Young's modulus substantially less than that of the diaphragm. First and second electrodes are connected to the diaphragm through the lead-out arm and to the substrate through polysilicon via fillings, respectively, and thereby establish a variable capacitor circuit for acoustic sensing.

Silicon microphone with softly constrained diaphragm

A MEMS package and a method for its forming are described. The MEMS package has at least one MEMS device located on a flexible substrate. A metal structure surrounds the at least one MEMS device wherein a bottom surface of the metal structure is attached to the flexible substrate and wherein a portion of the flexible substrate is folded over a top surface of the metal structure and attached to the top surface of the metal structure thereby forming the MEMS package.

Growing community of inventors

Singapore, Singapore

Wang Zhe